Spring bending machine



1945. F. J. HORTON SPRING BENDING MACHINE Filed April 26, 1943 5 Sheets-Sheet l INVENTOR 772121 X .73 florid/ Nov. 13, 1945. F. J. HORTON SPRING BENDING MACHINE Filed April 26, 1943 5 Sheets-Sheet 2 INVENTOR 7'72n?% J? #412 BY W,%

ATTORNE Y 1945. F. J. HORTON SPRING BENDING MACHINE Filed April 26, 1943 5 Sheets-Sheet 3 I N VENTOR Nov. 13, 1945. F, HORTON 2,389,055

SPRING BENDING MACHINE Filed April 26, 1945 5 Sheets-Sheet 4 INVENTOR 7"rarz% 7. Hprfo A TTORNE Y Nov. 13, 1945.

F. J. HORTON SPRING BENDING MACHINE Filed April 26, 1943 5 She ets-Sheet 5 INVENTOR Wa27% J7 Harfov.

ATTORNEY-5.

Patented Nov, 13, 1945 SPRING BENDING MACHINE Frank J. Horton, Detroit, Mich, assignor to No- Sag Spring Company, Macomb County, Mich, a corporation of Michigan Application April 26, 1943, Serial No. 484,565

11 Claims.

This invention relates to spring bending machines and particularly to a machine for bending the end convolutions of sinuous spring strips to form hooks on the ends thereof.

The sinuous sprin strip, on which hooks are to be formed by the machine embodying this invention, are similar to that illustrated, described and claimed in the reissue patent to Karl Kaden,

No. Re. 21,263, issued November 14, 1939, and assigned to the assignee of the present invention. This spring is formed of wire bent back and forth in zigzag relation and rolled on an arc of small radius along its longitudinal dimension to provide an inherent set against downward deflection when the ends are extended and secured to opposite sides of a frame. Suitable clips are employed for engaging the ends of the strip and for retaining the ends extended when the clips are attached to the frame.

The present invention embodies a machine for upsetting the end convolutions of the strip on its longitudinal axis and bending the convolu tion downwardly in the plane of the axis to form hooks at the ends of the strip extending below its top surface. The machine has a pair of bending heads adjacently disposed to each other to receive both ends of a strip which may be operated on at the same time or upon the ends of two separate strips.

The end of the strip in each head is engaged by a pin which extends through the convolution adjacent to the one to be bent, to retain the strip in predetermined position in the bending head. The bending head is provided with a slot which engages the endmost convolution and twists the convolution 90 to the plane of the strip. while bending the convolution 90 in the opposite direction into the plane to the longitudinal axis of the strip.

A fly wheel on the machine is driven by a motor, which is connected to an operating shaft by a clutch, which, when actuated, rotates the shaft through 360", which is sufficient to perform the bending operations. The shaft drives a rack connected with the operating head for revolving the head through the 90 movement. The bending die is pivoted on the head and is driven by a beveled gear meshed with a stationary beveled gear carried by the head. This produces a rota tion of the die when the head is revolved to produce the compound bending movement of the convolution at the end of the strip.

It is only necessary for the operator to insert the ends of a strip into the heads and to depress a foot pedal for throwing in the clutch, to first lock the erids in the heads and thereafter to drive,

the heads to bend the ends in the desired manher. After a single rotation-of the shaft, the

clutch automatically'throws out, irrespective as to whether or not the foot pedal is retained in depressed position. When the foot pedal is released, the securing pins are withdrawn from the spring ends, which may then be removed from the heads.

Accordingly, the main objects of this invention are: to provide a bending head for spring strips, which twist the end to the plane of the strip while bending the strip on its longitudinal axis to extend therebelow; to provide a bending machine with a pair of bending heads which are positioned to receive both ends of a strip and to bend hooks thereon in a single operation of the machine; to provide locking pins for the ends of the spring strips, which retain the ends in position when hooks are bent thereon; to provide a machine with a clutch, which operates to drive the shaft through a single revolution each time the clutch is actuated, for operating pins for securing the strip in position, and for twisting and bending the ends to form hooks thereon, and, in general, to provide a machine for bending hooks on the ends of a springstrip, which is simple in construction, positive in operation and economical of manufacture.

Other objects and features of novelty in this invention will be either specifically pointed out, or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings, wherein:

Figure 1 is a broken plan view of a spring bending machine embodying features of this invention:

Fig. 2 is a sectionalview of the structure illustrated in Fig. 1, taken on the line 2--2 thereof;

Fig. 3 is a view in elevation of a bending head of the machine illustrated in Fig. 1, as viewed from line 3-3 thereof;

Fig. 4 is an end view of the structure illustrated I in Fig. 3, as viewed from line 44 thereof;

Fig. 5 is a sectional view of the structure illustrated in Fig. 3, .taken on the line 5-5 thereof;

Fig. 6 is a sectional viewof the structure illustrated in Fig. 2, taken from line 66 thereof;

Fig. 7 is a sectional view of the structure, as

-- illustrated in Fig. 3, taken on the line 'l-l thereof;

Fig. 8 are views of the end of the spring strip before and after the bending operation is performed thereon;

Fig. 9 is a sectional view of the structure illustrated in Fig. 1, taken on the line 9-9 thereof, in the retracted position of the foot pedal;

Fig. 10 is a view of the structure illustrated in Fig. 9, before the downward movement of the foot pedal has been completed; and,

Fig. 11 is a sectional view of the structure illustrated in Fig. 9, taken on the line |I-|I thereof. I

The machine embodies a base I-2 which may be mounted on a bench, or which may be supported on a pedestal in the conventional manner. The undersurface of the base is provided with a bracket I3, in which a shaft I4 is journaled, The shaft is secured to a clutch element I5 by suitable means such as a key. The clutch element I5 is disposed adjacent to a hub I 6 on a fly wheel I1, which is rotatably mounted on a shaft I4. The fly wheel is driven by a belt I8 from a motor not herein illustrated.

The hub I6, as illustrated in Figure 11, is provided with a recess I9 in which a detent 2| is urged by a spring 22, A projecting finger 23 extends from side of the detent 2| to operate in a slot 24 in the clutch I5. A clutch finger 25 is pivoted on a bracket 26 by a pin 21, and is urged toward the clutch I5 by a spring 28. The finger is provided with a sloping surface 29, which engages the projecting finger 23 as the clutch I5 rotates in a clockwise direction, urging the finger 23 to the left, as viewed in Figure 11, to retract the detent 2| from the recess I9, to thereby release the clutch and shaft from the boss I6 and fly wheel I1 after a single revolution thereof. A brake band 3| engages a brake drum 32 provided in the extension of the clutch I5, which is adjusted to produce a predetermined braking force for preventing the overrun of the shaft when separated from the fly wheel.

Each time the clutch finger 25 is raised from the clutch drum 20, the finger 23 is released to permit the detent 2| to be urged to the right, as viewed in Figure 11, to project into the recess I9 as the hub I6 rotates, to produce the rotation of the clutch and the shaft I4. Releasing mechanism is provided, which permits the clutch finger 25 to immediately return to a position in which the sloping surface 29 will engage the projecting finger 23 to retract the detent 2| at the end of a single revolution of the clutch and shaft.

The shaft is provided with an eccentric pin 33 attached to a block 34, which is adjustably positioned within a channel shaped block 35 by the bolts 36. The relation between the axis of the eccentric pin 33 may be adjusted relative to the axis of the shaft I4 to change the throw of the eccentric. A roller 31 is secured on the eccentric pin 33, to operate in a channel shaped block 38, which is supported on a vertical slide 39. The vertical slide is supported in a channel shaped block 4| and is retained therein by the gibs 42. The block 39 has a rod 43 threaded, or otherwise secured to is upper end which projects through an aperture 44 in the top portion of the base I2. The upper end of the rod 43 has a rack 45 secured thereto with teeth 46 meshed with the teeth 41 of the pinion gear 48, which is supported on a trunnion 49 of a yoke element 5| and secured against rotation relative to the yoke element by a key 52.

The gear and pinion are mounted within a housing 53, which projects from one end of a base portion 54, from which a. standard 55 extends. The trunnion 49 of the yoke element 5| is journaled in a boss 56 on the side of the housing 53 in aligned relation with a pin 51 projecting from the standard 55 on which the opposite end 58 of the yoke 5| is joumaled, The inner- -face of the standard 55 has a bevel gear 59 secured thereto by a plurality of screws 69, 6| and 62. The screws 6| and 62 project through slots 63 in the bracket 55, which are disposed concentric to the axis of the pin 51 so as to permit the beveled gear to be adjusted about the pin 51. The web of the yoke is provided with a boss 64 through which a shaft 65 extends, secured in position by a washer 66. The shaft 65 is supported in the yoke 5| for rotation about its axis as the yoke is revolved about the axis of its trunnion 49 disposed normal to the axis of the shaft. A bevel gear 61 is supported by the shaft 65 having a pluralit of teeth meshed with the teeth of the bevel gear 59. The gear is retained in position by the head 68 on the lower end of the shaft 65. The gear 61 is keyed, or otherwise secured, to the shaft 65 to drive the shaft in rotation for turning the head 68, which produces the bending of the end of the wire as the yoke 5| is revolved about the axis of the trunnion 49 and pin 51.

The head 68 has a slot 69 for receiving the end convolution of the spring strip. The slot 69 is disposed in aligned relation with a slot 1| in a block 12, which is secured to the base portion 54 by screws 10. The block 12 has a central slot 13 in which a lever 14 is mounted for oscillating movement on a pin 15. A slot 16 is also provided in the block I2, communicating with the slots 13 and 1| A pin 11 is mounted in the slot 16, having a recess 18 for receiving the end 19 of the lever 14. The pin is operated by the lever into the slot 1|, to engage the next adjacent convolurespectively, The arm 84 of the bell crank 83 is connected by a link 85 to a bell crank 86. The arm 81 of the bell crank 82 has its end 88 projected into a notch 89 in the arm 84 of the bell crank 83, centrally between the pivots of the bell crank so as to produce the same degree of movement to the levers 14 when the link 85 is actuated.

The cam finger 25 is actuated by a plunger 9|, carried by a link 92 pivoted on the bracket 93 by the pin 94. A spring 95 urges the plunger out of the end of the link into abutting relation with the finger 25, limited by a pin 96 which is carried by the plunger and which operates in a slot 91. A rod 98 is attached to the opposite end of the link 92 and projects toward the floor, where it is attached to a foot lever (not shown). The pin 99 which joins the rOd 94 to the end of the link 92 projects outwardly, as illustrated in Fig. 1, in a position to engage an arm IOI of the bell crank 86. The projecting pin 99 engages the arm I III when the foot pedal is released and the rod 98 is urged upwardly by a spring (not illustrated) for'moving the links 14 toward each other to thereby retract the locking pins 11 after the bending operation. Springs I02 on the links 14 operate the links in the opposite direction when the pin 99 is moved downwardly with the rod 98 at the beginning of the operation.

This downward movement of the rod 98 raises the clutch finger 25 from the clutch drum 20 an amount suflicient to release the finger 23, after which the projecting end I03 'of the plunger 9| rides over the projecting portion I04 of the clutch finger to permit the spring 28 to immediately return the finger 25 within the drum 20 in position to intercept the projecting finger 23 to retract the plunger after a single revolution of the clutch and shaft Id.

In Fig. 8, a. sinuously formed wire strip I06 is illustrated having the end convolution I'I cut off at I08. The convolution I0I is twisted through 90 and bent backward upon the longitudinal axis of the strip, as illustrated at I09. To produce this bending operation, the strip I06 has one or both ends inserted in one or both of the bending heads, as illustrated in Fig. 1, and the foot pedal is then operated to move the rod 98 downwardly. The movement of the rod downwardly releases the support, of the bell crank 86,

which is rocked in acounter-clockwise direction by the springs I02 to move the lower end of the links I0 away from each other. This moves the pins 'I'I forwardly to project through the convolution III to securely retain or lock the'end of the strip in the slot II of the block I2, as illustrated in Fig. 5. The movement of the rod downwardly raises the clutch finger 25 to produce the single revolution of the shaft I4 as explained hereinabove. The single rotation of the shaft I i revolves the eccentric pin 3'3, which produces the reciprocation of the slide 39 and the rod 43, which in turn reciprocate 'the'rack B5.

The downward movement of the rack 45 rotates the pinion 48, which revolves the yoke 5I on the trunnion 49 and pin 51, to bend the loop end I0! forwardly in the plane of the strip. During this action, the beveled gear 61 is rotated on the stationary beveled gear 59, to twist theend along the axis of the wire at the intersection with the axis of the trunnion 49. This compound bending movement will occur on the centerline of the spring strip since the concentration of both bending forces occur at this point. At the end of the operation, the loop end I0'I will be disposed as illustrated in Fig. 8, aligned on.the axis of the strip and disposed beneath the plane of the strip. The degree of bending produced to the end loop is adjusted by regulating the throw of the eccentric pin 33, which regulates the degree of movement of the rack 35, which in turn regulates the degree of movement of the yoke 5|.

After the bending operation, the release of the foot pedal returns the rod 90 upwardly to rock the link 02 clockwise. The plunger BI is moved relative to the clutch finger 25, to have the projecting end I03 of the pin 0| engage the projection I00 on the finger. This upward movement of the rod 98 produces the engagement of the projecting pin 99 with the arm II of the bell crank 86, which operates the rod 85, the bell cranks 82 and 83 and the links 8| to move the lower ends of the levers I4 toward each other to move the pins 'I'I out of engagement with the convolution I II of the spring strip, the trips are then free to be withdrawn from the slot 'II of the block I2.

The motor continues to drive the fiy wheel IT and for each operation of the device the clutch connects the shaft to the fiy wheel to rotate it through 360. The single revolution of the shaft produces the bending of the end convolutions of the spring strips. Both ends of the same strip or an end of two separate strips may be bent in a single operation of the device.

What is claimed is:

1. In a bending machine, means for clamping A ber carried by the yoke in the plane of the strip' having means for engaging said end loop, and

an element to be bent in fixed position therein, a rotatable member. engaging an end of the element and being rotatable, about one axis, a remember engaging the end of the element and being rotatable about one axis, a support for said member which tilts the member about a second axi and about the point at which the element is .to be bent, and means for simultaneously tilting and rotating said member for bending said end.

3. In a machine for bending the end convolution of a wire strip, means for supporting the end of the strip in position to be bent, a rotatable member engaging said convolution and being rotatable about one axis, means for tilting said rotatable member about a second axis and about the point at which the strip'is to be bent, and means for simultaneously tilting and rotating said member for bending said convolution.

4. In a machine for bending the end convolution of a 'sinuous spring strip to form a hook on the end thereof, a support for the end of the strip, means for locking the strip in the support, rotatable means operable about one axis for engaging the convolution, means for tilting said rotatable means about another axis and about the point at which the strip is to be bent, and means for tilting and rotating said means simultaneously.

5. In a machine for bending hooks on the end of spring strips having an open loop which is presenting toward one side of thestrip, of means for supporting an end in position to be bent, means for locking said strip in said position, a yoke extending over said strip in position to be tilted in the plane of the strip, a rotatable memmeans for revolving said yoke and rotating said member simultaneously to twist the loop through as it is bent 90 by the yoke.

6. In a machine for bending hooks on the end of spring strips having an open loop which is presenting toward one side of the strip, of means for supporting an end in position to be bent, means for locking said strip in said position, a yoke extending over said strip in position to be tilted in the plane of the strip, a rotatable member carried by the yoke in the plane of the strip hav ing means for engaging said end loop, a fixed beveled gear, a beveled gear meshing with said fixed gear and secured to the rotatable member, and means for revolving said yoke to tilt said rotatable means while it is rotated by the action of said bevel gears to simultaneously bend the loop as it is twisted.

'7. In a device for bending a hook on the end of a spring strip having an open loop which is presenting toward one side of the strip, means for holding the strip in position to be bent, and means engaging said loop for twisting it through 90as it is bent,90 to the plane of the strip and transversely to the axis about which twisting occurs.

8.' In a device for bending a hook on the end of a spring strip having an open loop which is presenting toward one side of the strip, means for holding the strip in position to be bent, rotatable means engaging said loop, a yoke mounted on trunnions supporting said rotatable means,

a fixed bevel gear through which the trunnion revolves, a bevel gear on said rotatable means meshed with the fixed bevel gear, and a gear on one of said trunnions by which the yoke is tilted and the rotatable means is rotated.

9. In a devicei'or bending a hook on the end of a spring strip having an open loop which is presenting toward one side of the. strip, means for holding the strip in position to be bent, ro-

tatable means engaging said loop, a yoke mounted on trunnions supporting said rotatable means, a

able means engaging said loop, a yoke mounted on trunnions supporting said rotatable means, a

said last gear, and an fixed bevel gear through whichthe trunnion revolves, a bevel gear on. said rotatable means meshed with the fixed'bevel gear,'-a gear on one of said trunnions by which the yoke is'tilted and the rotatable means is rotated, a rack for rotating eccentric for driving said rack.

11. In a device for bending'a hook on the end '01 a spring strip having an open loop which is presenting toward one side 01' the strip, means for holding the strip in position to be bent, rotatable means engaging said loop, a yoke mounted on trunnions supporting said rotatable means, a

fixed bevel gear through which the trunnion revolves, a bevel gear on said rotatable means meshed with the fixed bevel gear, a gear on one of said trunnions by which the, yoke is tilted and the 'rotatable means is rotated, a rack for rotating said last gear, an eccentric for driving said rack, a base for supporting a pair of said devices.

driving means for operating the eccentric of and each device simultaneously.

I FRANK J. HORTON. 

